1. Field of the Invention
The present invention relates to an automatic document feeder, an image forming device, and an image reading device.
2. Description of the Related Art
In recent years, there has been higher demand for reduction in the sound of copiers than ever before. For example, with regard to the noise standard of the German environment standard (BAM), although the target is conventionally the noise level of a copier alone, the range of targets has been recently expanded to the noise level of, not only a copier alone, but also an image forming device that includes an automatic document feeder (ADF), which is conventionally treated as a peripheral device.
Furthermore, there is a market demand for reduction in, not only the normal operation sound, but also noise that occurs during an initialization operation to initialize the state of the device when it is started up, what is called initialization sound.
The initialization operation is performed based on the assumption of the occurrence of the state where a document remains at the position where it cannot be detected by a sensor within the device or the state where a unit is not in the home position, which is caused when the user moves a unit while the power source of the image forming device is off, the power source is suddenly disconnected, or the like.
Usually, in the case of image forming devices, such as copiers, in which ADFs are implemented, a user often leaves it as the main power source is on so that the user may use it instantaneously when he/she wants to. Therefore, there are disclosed image forming devices that perform the function to make an automatic switchover to a low-consumption power mode, what is called an energy saving mode, when the unused state continues for a certain period of time in order to reduce the power consumption during a stand-by state (for example, see Japanese Laid-open Patent Publication No. 2012-213133).
Japanese Laid-open Patent Publication No. 2012-213133 discloses the case where the image forming device performs different operations when the power source is turned on and when a return is made from the energy saving mode (hereafter, simply referred to as “energy saving return”) in the purpose of energy saving.
However, in conventional image forming devices that are disclosed in Japanese Laid-open Patent Publication No. 2012-213133, the initialization operation is uniformly performed when the power source of the main body of the image forming device is turned on or when a return is made from the energy saving mode. Therefore, there is a problem in that, the initialization operation is performed in a case where the initialization operation is not necessary, i.e., the case where each unit is in the home position and no documents remain within the device, and initialization sound occurs each time.
In view of the above, there is a need to provide an automatic document feeder, an image forming device, and an image reading device, which perform an initialization operation only when a predetermined condition is satisfied so that the noise of the device can be reduced.